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Naomi

Naomi icon Naomi logo

Overview

Sega’s NAOMI (New Arcade Operation Machine Idea) platform launched in 1998 as a Dreamcast-inspired arcade system. REG-Linux keeps it in the naomi metadata group and runs titles through the Flycast engines (standalone and libretro).

Quick reference

  • ROM folder: /userdata/roms/naomi
  • Accepted formats: .zip, .bin, .dat, .lst, .chd, .7z
  • Emulators: Flycast (standalone) and libretro: flycast
  • System group: naomi, arcade

Technical specifications

  • CPU: Hitachi SH-4 32-bit RISC processor running at 200 MHz.
  • Memory: 16 MB main RAM, 8 MB video RAM, 2 MB sound RAM matching Dreamcast-style architecture.
  • Display: PowerVR2 GPU pushing 640×480 textured polygons with perspective correction and per-pixel transparency.
  • Sound: Yamaha AICA DSP delivering 64-channel ADPCM audio plus MIDI-style synthesis, matching Dreamcast audio.

BIOS

Copy naomi.zip into /userdata/bios/ or /userdata/bios/dc/. Certain titles such as House of the Dead 2, Ferrari F355 Challenge and Airline Pilots rely on their own BIOS packs; keep them next to the primary archive. BD Dash also looks for a Dreamcast BIOS and optional HDD image.

ROM structure

Flycast expects either a single ROM ZIP or a ROM folder paired with a .chd file:

/userdata/roms/naomi/
├─ ikaruga.zip
└─ ikaruga/
   └─ gdl-0010.chd

.lst/.bin pairs mirror the Dreamcast naming conventions used by standard Flycast releases.

Emulator options

Open the Quick Menu ([HOTKEY] + south button) to tweak render resolution, widescreen hacks, shader packs, and per-core controller types (gamepad, mouse, light gun). The Flycast settings (flycast-config) expose the same toggles plus hi-res textures and community shaders. Adjust naomi.flycast_ratio, naomi.flycast_renderer, and naomi.flycast_anisotropic as needed.

  • For Wiimote/touch-themed boards (House of the Dead), ensure global.controller1_dc/global.controller2_dc is set to the proper peripheral.
  • If Free Play misbehaves, open the in-game System Menu (L3 + R3) and set the coin counter to 1 after enabling the service buttons.
  • Consult the Flycast compatibility list and generic support pages when issues persist.

Troubleshooting

  • When a title expects Wiimote/touch input (House of the Dead, etc.), pick the correct global.controller1_dc or global.controller2_dc peripheral before launching.
  • If Free Play or coin settings behave oddly, use the in-game System Menu (L3 + R3) to adjust the counters after enabling service buttons in RetroArch.
  • For broader issues consult the Flycast compatibility tracker and the generic support pages.
  • For Wiimote/touch-themed boards (House of the Dead), ensure global.controller1_dc/global.controller2_dc is set to the proper peripheral.
  • If Free Play misbehaves, open the in-game System Menu (L3 + R3) and set the coin counter to 1 after enabling the service buttons.
  • Consult the Flycast compatibility list and generic support pages when issues persist.